Birth date has a striking – and enduring – impact on academic performance, with summer babies doing worse in exams than September-born children at every stage of their school career, according to the Institute for Fiscal Studies.

Of September-born girls, some 60 per cent reach the government’s target for attaining good GCSEs; August-born girls fall short of it. The IFS, one of Britain’s most prestigious think-tanks, says this gulf means “access to further and higher education, and hence future success in the labour market, is likely to be significantly affected by the month in which you are born.”